90 day wonder 

Military officer whose source of commission is the 90-day OCS program. Characterized by feeling inferior to service academy grads. And rightly so.

I told that 90-day wonder that my socks have more time in service than he does.

90 day wonder by Salty Sam 02 August 20, 2003

90 day wonder 

a newly commissioned graduate of OCS or DCP

Not another 90 day wonder.

90 day wonder by The Return of Light Joker December 31, 2009